Vol. XIII. No. 311. 



THE AGRICULTUEAL NEWS. 



107 



THE PRESERVATION OF WOOD. 



This subject has been discussed from the industrial 

 aspect recently at a meeting of the Royal Society of Arts. 

 A paper on the subject was published in the journal of the 

 society for February 20, 1914. It is explained that wood 

 consists essentially of vessels and cells, the only solid parts 

 being the coats which form them. In the vessel is the sap 

 circulating during life, but on the death of the tree the sap 

 decomposes and is likely to cause decomposition of the hard 

 structure. The most common causes of decay are alternating 

 conditions of wetness and dryness, heat and cold and the 

 absence of ventilation. There are two kinds of deciy distin- 

 guished as wet rot and dry rot. The former occurs while 

 the tree is standing; the latter takes place only in dead wood 

 and is principally caused by fungi and boring insects. 



After giving an interesting account of the different 

 views which are held in regard to the manner in which 

 timber is able to absorb preservatives, the author proceeds to 

 discuss the various processes employed for preserving wood. 

 First of all the bichloride of mercury process or 'kianizing' is 

 described, which consists in steeping or soaking the wood in 

 a solution of bichloride of mercury or corrosive sublimate- 

 the solution generally used, con.sisting of 1 tt). of the salt to 

 99 lb. of water. The next process described is the zinc 

 chloride treatment. This consists in principle, in the destruc- 

 tion of the tendency possessed by certain vegetable and 

 animal substances to decay, by subjecting them to the action 

 of chloride of zinc. As in the case of creasoting, to be 

 described later, this treatment is generally carried on under 

 pressure. The zinc tannin process, dealt with next, is 

 described as a treatment of the wood with steam suffi- 

 cient to open the pores and expel the natural sap fol- 

 lowed by a vacuum requisite for the withdrawal of the 

 vapours and condensed steam. The antiseptic agent 

 used in this process consists of a solution of zinc 

 chloride and tannin. Perhaps the most common way 

 of treating wood with a view to prolonging its life 

 is by means of the dead oil of tar process, or, as it is 

 more commonly called, creasoting. In this process the wood 

 for treatment having been carefully dried, is steamed and 

 subjected in a retort to the action of a heated vacuum. The 

 creasote oil is then admitted and the temperature raised 

 slightly above the boiling point of the sap at the pressure in 

 the retort at the time. An important matter during the 

 course of this process seems to be the amount of pressure to 

 which the wood is subjected during impregnation. The 

 reader is referred to the paper acknowledged above for further 

 information in connexion with this process, which, in the 

 paper, is treated at great length. 



Of some special interest in the West Indies is the 

 saccharine solution process. The exact composition of the 

 .solution used is a secret, but it is stated to consist mainly 

 of sugar with a small percentage of arsenic added, and 

 probably .several other ingredients. The value of saccharine 

 solutions for the preservation of wood is said to have been 

 discovered from the fact that the timber of sugar vats is 

 found to be, to all intents and purposes, everlasting. It 

 would seem that a great advantage attending this process is 

 the circumstance that green woo'l may be satisfactorily 

 treated by it. 



Space will not permit reference to the numerous other 

 processes dealt with in the paper, though in concluding this 

 abstract the attention of those particularly interested in the 

 subject may de directed to the section of the paper dealing 

 with natural oils as preservative agents, and to the tables 

 showing absorption capacities and the cost of carrying out 

 the various processes. 



MONTSERRAT: REPORT ON THE BOTANIG 

 STATION, 191 .'-13. 



During the year under review the weather was some 

 what dry in Montserrat which limited to a considerabl 

 extent the yields of the principal crops, particularly cotton- 

 The amount of lint shipped during the 1912 13 season was 

 290,.390 a valued at £18,478. This shows a falling oflf 

 from the 1911-12 figures which were .544,607 ft)., value 

 £38,692. The average yield of cotton for the island was 

 approximately 142 lb. of lint per acre. In regard to limes, 

 231,700 gallons of raw juice were exported during the year 

 compared with an average output of 237,028 gallons for 

 the previous seven years. Muscovado sugar was shipped to 

 the value of about £2,000. As regards the minor industries 

 progress has been made in regard to the exports of papain, 

 bay oil and onions. 



Turning to the experimental work conducted at the 

 Botanic Station, the report shows that this has consisted 

 principally of selection work with cotton, miscellaneous 

 investigations in regard to the bay tree and provision crops, 

 together with the numerous observations concerning insect 

 pests and their control. The selection work with cotton 

 has been continued and has again been productive of 

 benefit to the growers of this crop in the island. Heaton 

 No. 9 can now be recommended as a variety suitable for 

 general cultivation. In connexion with the quality of lint, 

 some tests were made to find out whether any definite 

 differences occurred between the quality of first crop lint 

 and the quality of the second. A commercial valuation of 

 samples in London showed that the second crop lint was 

 undoubtedly inferior to the first. Of much interest among 

 the observations dealing with cotton is the explanation of 

 what has been called gin cutting. This effect has been 

 found to be due to an imperfect stationary knife in the 

 Montserrat ginneries, and there should be no reason now for 

 preventing the occurrence of this defect in future. 



Considerable attention has been given in Montserrat, 

 in an experimental way, to Egyptian varieties of cotton. 

 Sakellarides has again been found to grow vigorously but 

 a disadvantage attaching to its cultivation in the island 

 is the readiness with which the bolls are shed, thereby 

 necessitating a large number of pickings. The Egyptian 

 varieties, Abassi and Mitafifi, were for the first time tried 

 during the year under review. They gave a rather lower 

 yield than Sakellarides. Work with cotton hybrids has been 

 continued, the object in this work being to produce 

 a desirable cro.ss between St. Eustatius native and Sea Island 

 stains. Cotton manurial experiments were continued during 

 the year. 



In regard to the experimental work with crops other thin 

 cotton, reference may be made to the cultivation experiments 

 with lime trees; to the study of bay trees in regard to the 

 yield of oil, the time of reaping and differences in oil from 

 selected trees; and to the experiments with sweet potatoes in 

 connexion with early maturity and planting from vines mrsus 

 setts. As usual trials with ground nuts have been continued 

 and the Gambia variety has been found best suited to 

 conditions obtaining in Montserrat. 



